In this work we applied a systematic and model-independent method to study the
analytic structure of the IR Landau-gauge gluon and ghost propagators,
by using rational approximants. In particular, Padé approximants, partial
Padé approximants and also D-log Padé approximants were employed as fitting
functions to four-dimensional SU(2) lattice data [1]}, [2]}, [3]} of both propagators.
We stress that Refs. [4]}, [5]} also applied
Padé approximants to fit SU(3) lattice propagators and our main conclusions
are in agreement with their results. Notice, however, that in
our work the errors were carefully propagated, considering all the
correlations. In addition, we also estimated the systematic
uncertainty of the employed method and explored other types of
approximants: the partial Padés and the D-Log Padés.
